Understanding Network and CPU utilization is crucial for optimizing video call settings and ensuring that participants remain connected and communicating through the call.
Though, modern web browsers don't provide access to CPU information for security reasons. Using call metrics, we have derived a CPU load event that can indicate when either video encoding or decoding are resulting in a high CPU load.
Additionally, detecting and responding to changes in network performance are equally important when it comes to call quality. We expose simple network events that help your application adapt to variable network conditions.
network-quality-change event applies to video calls only.
Fires when the
quality of the network has changed.
threshold is an assessment of the current network quality, and can have the value
'very-low'. The threshold value is calculated from network stats averaged over an approximately 30-second rolling window. By default, we lower the bandwidth used for the call, when the network quality drops to low.
quality is a subjective calculation of the current network quality on a scale of 1-100, suitable for display in a user interface.
The event object holds the stats for both.
There are (currently) three possible network connection types:
Call setup and call management information flow through the
signaling network connection.
Audio and video flow through the
sfu network connections.
Generally, if a participant's
signaling connection is interrupted, the participant is temporarily offline. If we aren't able to reconnect within approximately 20 seconds, the participant will be ejected from the call.
sfu network connections are interrupted, remote audio and video tracks stop, for the participant. We will attempt to reconnect
sfu connections (and restore audio and video) as long as there is a live
The event object specifies which type of connection was affected (
'sfu'), the kind of connection event (
'interrupted'), and any other available information, like a participant's
session_id or the
The most common cause of
sfu connection interruptions is high packet loss on the participant's local wifi network.
Dive into network connection types
cpu-load-change event applies to video calls only.
Fires when the
cpuLoadState has changed.
cpuLoadStateis an assessment of the current CPU state, which can be either
cpuLoadStateReasoncan have values of:
highand video encoding is the primary cause for the high CPU load.
highand video decoding is the primary cause for the high CPU load.
highand specific functions in the Daily code are not completing within a specified interval.
When a high CPU load occurs, this means that the video call running on your website or in your app might experience a lower resolution and/or framerate. To reduce the load on the CPU, we recommend:
- lowering the outgoing video by calling
- requesting a lower simulcast layer by calling
- decreasing the amount of video subscriptions in large calls. More details on this article.
Taking these actions will result in decreased video quality, but it will help call participants remain connected and will help them to communicate without lost or delayed audio.